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 /* $DragonFly: src/sbin/ifconfig/ifmedia.c,v 1.6 2004/12/18 21:43:38 swildner Exp $ */
   4
   5 /*
   6  * Copyright (c) 1997 Jason R. Thorpe.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed for the NetBSD Project
  20  *      by Jason R. Thorpe.
  21  * 4. The name of the author may not be used to endorse or promote products
  22  *    derived from this software without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  27  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  28  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  29  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  30  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  31  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  32  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36
  37 /*
  38  * Copyright (c) 1983, 1993
  39  *      The Regents of the University of California.  All rights reserved.
  40  *
  41  * Redistribution and use in source and binary forms, with or without
  42  * modification, are permitted provided that the following conditions
  43  * are met:
  44  * 1. Redistributions of source code must retain the above copyright
  45  *    notice, this list of conditions and the following disclaimer.
  46  * 2. Redistributions in binary form must reproduce the above copyright
  47  *    notice, this list of conditions and the following disclaimer in the
  48  *    documentation and/or other materials provided with the distribution.
  49  * 3. All advertising materials mentioning features or use of this software
  50  *    must display the following acknowledgement:
  51  *      This product includes software developed by the University of
  52  *      California, Berkeley and its contributors.
  53  * 4. Neither the name of the University nor the names of its contributors
  54  *    may be used to endorse or promote products derived from this software
  55  *    without specific prior written permission.
  56  *
  57  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  58  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  59  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  60  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  61  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  62  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  63  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  64  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  65  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  66  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  67  * SUCH DAMAGE.
  68  */
  69
  70 #include <sys/param.h>
  71 #include <sys/ioctl.h>
  72 #include <sys/socket.h>
  73 #include <sys/sysctl.h>
  74 #include <sys/time.h>
  75
  76 #include <net/if.h>
  77 #include <net/if_dl.h>
  78 #include <net/if_types.h>
  79 #include <net/if_media.h>
  80 #include <net/route.h>
  81
  82 #include <ctype.h>
  83 #include <err.h>
  84 #include <errno.h>
  85 #include <fcntl.h>
  86 #include <stdio.h>
  87 #include <stdlib.h>
  88 #include <string.h>
  89 #include <unistd.h>
  90
  91 #include "ifconfig.h"
  92
  93 static void     domediaopt(const char *, int, int);
  94 static int      get_media_subtype(int, const char *);
  95 static int      get_media_options(int, const char *);
  96 static int      lookup_media_word(struct ifmedia_description *, const char *);
  97 static void     print_media_word(int, int);
  98 static void     print_media_word_ifconfig(int);
  99
 100 static struct ifmedia_description *get_toptype_desc(int);
 101 static struct ifmedia_type_to_subtype *get_toptype_ttos(int);
 102 static struct ifmedia_description *get_subtype_desc(int,
 103     struct ifmedia_type_to_subtype *ttos);
 104
 105 void
 106 media_status(int s, struct rt_addrinfo *info __unused)
 107 {
 108         struct ifmediareq ifmr;
 109         int *media_list, i;
 110
 111         memset(&ifmr, 0, sizeof(ifmr));
 112         strncpy(ifmr.ifm_name, name, sizeof(ifmr.ifm_name));
 113
 114         if (ioctl(s, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0) {
 115                 /*
 116                  * Interface doesn't support SIOC{G,S}IFMEDIA.
 117                  */
 118                 return;
 119         }
 120
 121         if (ifmr.ifm_count == 0) {
 122                 warnx("%s: no media types?", name);
 123                 return;
 124         }
 125
 126         media_list = (int *)malloc(ifmr.ifm_count * sizeof(int));
 127         if (media_list == NULL)
 128                 err(1, "malloc");
 129         ifmr.ifm_ulist = media_list;
 130
 131         if (ioctl(s, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0)
 132                 err(1, "SIOCGIFMEDIA");
 133
 134         printf("\tmedia: ");
 135         print_media_word(ifmr.ifm_current, 1);
 136         if (ifmr.ifm_active != ifmr.ifm_current) {
 137                 putchar(' ');
 138                 putchar('(');
 139                 print_media_word(ifmr.ifm_active, 0);
 140                 putchar(')');
 141         }
 142
 143         putchar('\n');
 144
 145         if (ifmr.ifm_status & IFM_AVALID) {
 146                 printf("\tstatus: ");
 147                 switch (IFM_TYPE(ifmr.ifm_active)) {
 148                 case IFM_ETHER:
 149                         if (ifmr.ifm_status & IFM_ACTIVE)
 150                                 printf("active");
 151                         else
 152                                 printf("no carrier");
 153                         break;
 154
 155                 case IFM_FDDI:
 156                 case IFM_TOKEN:
 157                         if (ifmr.ifm_status & IFM_ACTIVE)
 158                                 printf("inserted");
 159                         else
 160                                 printf("no ring");
 161                         break;
 162                 case IFM_IEEE80211:
 163                         /* XXX: Different value for adhoc? */
 164                         if (ifmr.ifm_status & IFM_ACTIVE)
 165                                 printf("associated");
 166                         else
 167                                 printf("no carrier");
 168                         break;
 169                 }
 170                 putchar('\n');
 171         }
 172
 173         if (ifmr.ifm_count > 0 && supmedia) {
 174                 printf("\tsupported media:\n");
 175                 for (i = 0; i < ifmr.ifm_count; i++) {
 176                         printf("\t\t");
 177                         print_media_word_ifconfig(media_list[i]);
 178                         putchar('\n');
 179                 }
 180         }
 181
 182         free(media_list);
 183 }
 184
 185 void
 186 setmedia(const char *val, int d, int s, const struct afswtch *afp)
 187 {
 188         struct ifmediareq ifmr;
 189         int first_type, subtype;
 190
 191         memset(&ifmr, 0, sizeof(ifmr));
 192         strncpy(ifmr.ifm_name, name, sizeof(ifmr.ifm_name));
 193
 194         ifmr.ifm_count = 1;
 195         ifmr.ifm_ulist = &first_type;
 196         if (ioctl(s, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0) {
 197                 /*
 198                  * If we get E2BIG, the kernel is telling us
 199                  * that there are more, so we can ignore it.
 200                  */
 201                 if (errno != E2BIG)
 202                         err(1, "SIOCGIFMEDIA");
 203         }
 204
 205         if (ifmr.ifm_count == 0)
 206                 errx(1, "%s: no media types?", name);
 207
 208         /*
 209          * We are primarily concerned with the top-level type.
 210          * However, "current" may be only IFM_NONE, so we just look
 211          * for the top-level type in the first "supported type"
 212          * entry.
 213          *
 214          * (I'm assuming that all supported media types for a given
 215          * interface will be the same top-level type..)
 216          */
 217         subtype = get_media_subtype(IFM_TYPE(first_type), val);
 218
 219         strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
 220         ifr.ifr_media = (ifmr.ifm_current & ~(IFM_NMASK|IFM_TMASK)) |
 221             IFM_TYPE(first_type) | subtype;
 222
 223         if (ioctl(s, SIOCSIFMEDIA, (caddr_t)&ifr) < 0)
 224                 err(1, "SIOCSIFMEDIA");
 225 }
 226
 227 void
 228 setmediaopt(const char *val, int d, int s, const struct afswtch *afp)
 229 {
 230
 231         domediaopt(val, 0, s);
 232 }
 233
 234 void
 235 unsetmediaopt(const char *val, int d, int s, const struct afswtch *afp)
 236 {
 237
 238         domediaopt(val, 1, s);
 239 }
 240
 241 static void
 242 domediaopt(const char *val, int clear, int s)
 243 {
 244         struct ifmediareq ifmr;
 245         int *mwords, options;
 246
 247         memset(&ifmr, 0, sizeof(ifmr));
 248         strncpy(ifmr.ifm_name, name, sizeof(ifmr.ifm_name));
 249
 250         /*
 251          * We must go through the motions of reading all
 252          * supported media because we need to know both
 253          * the current media type and the top-level type.
 254          */
 255
 256         if (ioctl(s, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0)
 257                 err(1, "SIOCGIFMEDIA");
 258
 259         if (ifmr.ifm_count == 0)
 260                 errx(1, "%s: no media types?", name);
 261
 262         mwords = (int *)malloc(ifmr.ifm_count * sizeof(int));
 263         if (mwords == NULL)
 264                 err(1, "malloc");
 265
 266         ifmr.ifm_ulist = mwords;
 267         if (ioctl(s, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0)
 268                 err(1, "SIOCGIFMEDIA");
 269
 270         options = get_media_options(IFM_TYPE(mwords[0]), val);
 271
 272         free(mwords);
 273
 274         strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
 275         ifr.ifr_media = ifmr.ifm_current;
 276         if (clear)
 277                 ifr.ifr_media &= ~options;
 278         else
 279                 ifr.ifr_media |= options;
 280
 281         if (ioctl(s, SIOCSIFMEDIA, (caddr_t)&ifr) < 0)
 282                 err(1, "SIOCSIFMEDIA");
 283 }
 284
 285 /**********************************************************************
 286  * A good chunk of this is duplicated from sys/net/ifmedia.c
 287  **********************************************************************/
 288
 289 static struct ifmedia_description ifm_type_descriptions[] =
 290     IFM_TYPE_DESCRIPTIONS;
 291
 292 static struct ifmedia_description ifm_subtype_ethernet_descriptions[] =
 293     IFM_SUBTYPE_ETHERNET_DESCRIPTIONS;
 294
 295 static struct ifmedia_description ifm_subtype_ethernet_aliases[] =
 296     IFM_SUBTYPE_ETHERNET_ALIASES;
 297
 298 static struct ifmedia_description ifm_subtype_ethernet_option_descriptions[] =
 299     IFM_SUBTYPE_ETHERNET_OPTION_DESCRIPTIONS;
 300
 301 static struct ifmedia_description ifm_subtype_tokenring_descriptions[] =
 302     IFM_SUBTYPE_TOKENRING_DESCRIPTIONS;
 303
 304 static struct ifmedia_description ifm_subtype_tokenring_aliases[] =
 305     IFM_SUBTYPE_TOKENRING_ALIASES;
 306
 307 static struct ifmedia_description ifm_subtype_tokenring_option_descriptions[] =
 308     IFM_SUBTYPE_TOKENRING_OPTION_DESCRIPTIONS;
 309
 310 static struct ifmedia_description ifm_subtype_fddi_descriptions[] =
 311     IFM_SUBTYPE_FDDI_DESCRIPTIONS;
 312
 313 static struct ifmedia_description ifm_subtype_fddi_aliases[] =
 314     IFM_SUBTYPE_FDDI_ALIASES;
 315
 316 static struct ifmedia_description ifm_subtype_fddi_option_descriptions[] =
 317     IFM_SUBTYPE_FDDI_OPTION_DESCRIPTIONS;
 318
 319 static struct ifmedia_description ifm_subtype_ieee80211_descriptions[] =
 320     IFM_SUBTYPE_IEEE80211_DESCRIPTIONS;
 321
 322 static struct ifmedia_description ifm_subtype_ieee80211_aliases[] =
 323     IFM_SUBTYPE_IEEE80211_ALIASES;
 324
 325 static struct ifmedia_description ifm_subtype_ieee80211_option_descriptions[] =
 326     IFM_SUBTYPE_IEEE80211_OPTION_DESCRIPTIONS;
 327
 328 static struct ifmedia_description ifm_subtype_shared_descriptions[] =
 329     IFM_SUBTYPE_SHARED_DESCRIPTIONS;
 330
 331 static struct ifmedia_description ifm_subtype_shared_aliases[] =
 332     IFM_SUBTYPE_SHARED_ALIASES;
 333
 334 static struct ifmedia_description ifm_shared_option_descriptions[] =
 335     IFM_SHARED_OPTION_DESCRIPTIONS;
 336
 337 struct ifmedia_type_to_subtype {
 338         struct {
 339                 struct ifmedia_description *desc;
 340                 int alias;
 341         } subtypes[5];
 342         struct {
 343                 struct ifmedia_description *desc;
 344                 int alias;
 345         } options[3];
 346 };
 347
 348 /* must be in the same order as IFM_TYPE_DESCRIPTIONS */
 349 static struct ifmedia_type_to_subtype ifmedia_types_to_subtypes[] = {
 350         {
 351                 {
 352                         { &ifm_subtype_shared_descriptions[0], 0 },
 353                         { &ifm_subtype_shared_aliases[0], 1 },
 354                         { &ifm_subtype_ethernet_descriptions[0], 0 },
 355                         { &ifm_subtype_ethernet_aliases[0], 1 },
 356                         { NULL, 0 },
 357                 },
 358                 {
 359                         { &ifm_shared_option_descriptions[0], 0 },
 360                         { &ifm_subtype_ethernet_option_descriptions[0], 0 },
 361                         { NULL, 0 },
 362                 },
 363         },
 364         {
 365                 {
 366                         { &ifm_subtype_shared_descriptions[0], 0 },
 367                         { &ifm_subtype_shared_aliases[0], 1 },
 368                         { &ifm_subtype_tokenring_descriptions[0], 0 },
 369                         { &ifm_subtype_tokenring_aliases[0], 1 },
 370                         { NULL, 0 },
 371                 },
 372                 {
 373                         { &ifm_shared_option_descriptions[0], 0 },
 374                         { &ifm_subtype_tokenring_option_descriptions[0], 0 },
 375                         { NULL, 0 },
 376                 },
 377         },
 378         {
 379                 {
 380                         { &ifm_subtype_shared_descriptions[0], 0 },
 381                         { &ifm_subtype_shared_aliases[0], 1 },
 382                         { &ifm_subtype_fddi_descriptions[0], 0 },
 383                         { &ifm_subtype_fddi_aliases[0], 1 },
 384                         { NULL, 0 },
 385                 },
 386                 {
 387                         { &ifm_shared_option_descriptions[0], 0 },
 388                         { &ifm_subtype_fddi_option_descriptions[0], 0 },
 389                         { NULL, 0 },
 390                 },
 391         },
 392         {
 393                 {
 394                         { &ifm_subtype_shared_descriptions[0], 0 },
 395                         { &ifm_subtype_shared_aliases[0], 1 },
 396                         { &ifm_subtype_ieee80211_descriptions[0], 0 },
 397                         { &ifm_subtype_ieee80211_aliases[0], 1 },
 398                         { NULL, 0 },
 399                 },
 400                 {
 401                         { &ifm_shared_option_descriptions[0], 0 },
 402                         { &ifm_subtype_ieee80211_option_descriptions[0], 0 },
 403                         { NULL, 0 },
 404                 },
 405         },
 406 };
 407
 408 static int
 409 get_media_subtype(int type, const char *val)
 410 {
 411         struct ifmedia_description *desc;
 412         struct ifmedia_type_to_subtype *ttos;
 413         int rval, i;
 414
 415         /* Find the top-level interface type. */
 416         for (desc = ifm_type_descriptions, ttos = ifmedia_types_to_subtypes;
 417             desc->ifmt_string != NULL; desc++, ttos++)
 418                 if (type == desc->ifmt_word)
 419                         break;
 420         if (desc->ifmt_string == NULL)
 421                 errx(1, "unknown media type 0x%x", type);
 422
 423         for (i = 0; ttos->subtypes[i].desc != NULL; i++) {
 424                 rval = lookup_media_word(ttos->subtypes[i].desc, val);
 425                 if (rval != -1)
 426                         return (rval);
 427         }
 428         errx(1, "unknown media subtype: %s", val);
 429         /* NOTREACHED */
 430 }
 431
 432 static int
 433 get_media_options(int type, const char *val)
 434 {
 435         struct ifmedia_description *desc;
 436         struct ifmedia_type_to_subtype *ttos;
 437         char *optlist, *optptr;
 438         int option = 0, i, rval = 0;
 439
 440         /* We muck with the string, so copy it. */
 441         optlist = strdup(val);
 442         if (optlist == NULL)
 443                 err(1, "strdup");
 444
 445         /* Find the top-level interface type. */
 446         for (desc = ifm_type_descriptions, ttos = ifmedia_types_to_subtypes;
 447             desc->ifmt_string != NULL; desc++, ttos++)
 448                 if (type == desc->ifmt_word)
 449                         break;
 450         if (desc->ifmt_string == NULL)
 451                 errx(1, "unknown media type 0x%x", type);
 452
 453         /*
 454          * Look up the options in the user-provided comma-separated
 455          * list.
 456          */
 457         optptr = optlist;
 458         for (; (optptr = strtok(optptr, ",")) != NULL; optptr = NULL) {
 459                 for (i = 0; ttos->options[i].desc != NULL; i++) {
 460                         option = lookup_media_word(ttos->options[i].desc, optptr);
 461                         if (option != -1)
 462                                 break;
 463                 }
 464                 if (option == 0)
 465                         errx(1, "unknown option: %s", optptr);
 466                 rval |= option;
 467         }
 468
 469         free(optlist);
 470         return (rval);
 471 }
 472
 473 static int
 474 lookup_media_word(struct ifmedia_description *desc, const char *val)
 475 {
 476
 477         for (; desc->ifmt_string != NULL; desc++)
 478                 if (strcasecmp(desc->ifmt_string, val) == 0)
 479                         return (desc->ifmt_word);
 480
 481         return (-1);
 482 }
 483
 484 static struct ifmedia_description *get_toptype_desc(int ifmw)
 485 {
 486         struct ifmedia_description *desc;
 487
 488         for (desc = ifm_type_descriptions; desc->ifmt_string != NULL; desc++)
 489                 if (IFM_TYPE(ifmw) == desc->ifmt_word)
 490                         break;
 491
 492         return desc;
 493 }
 494
 495 static struct ifmedia_type_to_subtype *get_toptype_ttos(int ifmw)
 496 {
 497         struct ifmedia_description *desc;
 498         struct ifmedia_type_to_subtype *ttos;
 499
 500         for (desc = ifm_type_descriptions, ttos = ifmedia_types_to_subtypes;
 501             desc->ifmt_string != NULL; desc++, ttos++)
 502                 if (IFM_TYPE(ifmw) == desc->ifmt_word)
 503                         break;
 504
 505         return ttos;
 506 }
 507
 508 static struct ifmedia_description *get_subtype_desc(int ifmw,
 509                                   struct ifmedia_type_to_subtype *ttos)
 510 {
 511         int i;
 512         struct ifmedia_description *desc;
 513
 514         for (i = 0; ttos->subtypes[i].desc != NULL; i++) {
 515                 if (ttos->subtypes[i].alias)
 516                         continue;
 517                 for (desc = ttos->subtypes[i].desc;
 518                     desc->ifmt_string != NULL; desc++) {
 519                         if (IFM_SUBTYPE(ifmw) == desc->ifmt_word)
 520                                 return desc;
 521                 }
 522         }
 523
 524         return NULL;
 525 }
 526
 527 static void
 528 print_media_word(int ifmw, int print_toptype)
 529 {
 530         struct ifmedia_description *desc;
 531         struct ifmedia_type_to_subtype *ttos;
 532         int seen_option = 0, i;
 533
 534         /* Find the top-level interface type. */
 535         desc = get_toptype_desc(ifmw);
 536         ttos = get_toptype_ttos(ifmw);
 537         if (desc->ifmt_string == NULL) {
 538                 printf("<unknown type>");
 539                 return;
 540         } else if (print_toptype) {
 541                 printf("%s", desc->ifmt_string);
 542         }
 543
 544         /*
 545          * Don't print the top-level type; it's not like we can
 546          * change it, or anything.
 547          */
 548
 549         /* Find subtype. */
 550         desc = get_subtype_desc(ifmw, ttos);
 551         if (desc != NULL)
 552                 goto got_subtype;
 553
 554         /* Falling to here means unknown subtype. */
 555         printf("<unknown subtype>");
 556         return;
 557
 558  got_subtype:
 559         if (print_toptype)
 560                 putchar(' ');
 561
 562         printf("%s", desc->ifmt_string);
 563
 564         /* Find options. */
 565         for (i = 0; ttos->options[i].desc != NULL; i++) {
 566                 if (ttos->options[i].alias)
 567                         continue;
 568                 for (desc = ttos->options[i].desc;
 569                     desc->ifmt_string != NULL; desc++) {
 570                         if (ifmw & desc->ifmt_word) {
 571                                 if (seen_option == 0)
 572                                         printf(" <");
 573                                 printf("%s%s", seen_option++ ? "," : "",
 574                                     desc->ifmt_string);
 575                         }
 576                 }
 577         }
 578         printf("%s", seen_option ? ">" : "");
 579 }
 580
 581 static void
 582 print_media_word_ifconfig(int ifmw)
 583 {
 584         struct ifmedia_description *desc;
 585         struct ifmedia_type_to_subtype *ttos;
 586         int i;
 587
 588         /* Find the top-level interface type. */
 589         desc = get_toptype_desc(ifmw);
 590         ttos = get_toptype_ttos(ifmw);
 591         if (desc->ifmt_string == NULL) {
 592                 printf("<unknown type>");
 593                 return;
 594         }
 595
 596         /*
 597          * Don't print the top-level type; it's not like we can
 598          * change it, or anything.
 599          */
 600
 601         /* Find subtype. */
 602         desc = get_subtype_desc(ifmw, ttos);
 603         if (desc != NULL)
 604                 goto got_subtype;
 605
 606         /* Falling to here means unknown subtype. */
 607         printf("<unknown subtype>");
 608         return;
 609
 610  got_subtype:
 611         printf("media %s", desc->ifmt_string);
 612
 613         /* Find options. */
 614         for (i = 0; ttos->options[i].desc != NULL; i++) {
 615                 if (ttos->options[i].alias)
 616                         continue;
 617                 for (desc = ttos->options[i].desc;
 618                     desc->ifmt_string != NULL; desc++) {
 619                         if (ifmw & desc->ifmt_word) {
 620                                 printf(" mediaopt %s", desc->ifmt_string);
 621                         }
 622                 }
 623         }
 624 }
 625
 626 /**********************************************************************
 627  * ...until here.
 628  **********************************************************************/