sys/geom/geom_mbr.c

   1 /*-
   2  * Copyright (c) 2002 Poul-Henning Kamp
   3  * Copyright (c) 2002 Networks Associates Technology, Inc.
   4  * All rights reserved.
   5  *
   6  * This software was developed for the FreeBSD Project by Poul-Henning Kamp
   7  * and NAI Labs, the Security Research Division of Network Associates, Inc.
   8  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
   9  * DARPA CHATS research program.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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/cdefs.h>
  34 __FBSDID("$FreeBSD$");
  35
  36 #include <sys/param.h>
  37 #include <sys/errno.h>
  38 #include <sys/endian.h>
  39 #include <sys/systm.h>
  40 #include <sys/sysctl.h>
  41 #include <sys/kernel.h>
  42 #include <sys/fcntl.h>
  43 #include <sys/malloc.h>
  44 #include <sys/bio.h>
  45 #include <sys/lock.h>
  46 #include <sys/mutex.h>
  47 #include <sys/md5.h>
  48 #include <sys/proc.h>
  49
  50 #include <sys/diskmbr.h>
  51 #include <sys/sbuf.h>
  52 #include <geom/geom.h>
  53 #include <geom/geom_slice.h>
  54
  55 FEATURE(geom_mbr, "GEOM DOS/MBR partitioning support");
  56
  57 #define MBR_CLASS_NAME "MBR"
  58 #define MBREXT_CLASS_NAME "MBREXT"
  59
  60 static struct dos_partition historical_bogus_partition_table[NDOSPART] = {
  61         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
  62         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
  63         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
  64         { 0x80, 0, 1, 0, DOSPTYP_386BSD, 255, 255, 255, 0, 50000, },
  65 };
  66
  67 static struct dos_partition historical_bogus_partition_table_fixed[NDOSPART] = {
  68         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
  69         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
  70         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
  71         { 0x80, 0, 1, 0, DOSPTYP_386BSD, 254, 255, 255, 0, 50000, },
  72 };
  73
  74 static void
  75 g_mbr_print(int i, struct dos_partition *dp)
  76 {
  77
  78         printf("[%d] f:%02x typ:%d", i, dp->dp_flag, dp->dp_typ);
  79         printf(" s(CHS):%d/%d/%d", DPCYL(dp->dp_scyl, dp->dp_ssect),
  80             dp->dp_shd, DPSECT(dp->dp_ssect));
  81         printf(" e(CHS):%d/%d/%d", DPCYL(dp->dp_ecyl, dp->dp_esect),
  82             dp->dp_ehd, DPSECT(dp->dp_esect));
  83         printf(" s:%d l:%d\n", dp->dp_start, dp->dp_size);
  84 }
  85
  86 struct g_mbr_softc {
  87         int             type [NDOSPART];
  88         u_int           sectorsize;
  89         u_char          sec0[512];
  90         u_char          slicesum[16];
  91 };
  92
  93 /*
  94  * XXX: Add gctl_req arg and give good error msgs.
  95  * XXX: Check that length argument does not bring boot code inside any slice.
  96  */
  97 static int
  98 g_mbr_modify(struct g_geom *gp, struct g_mbr_softc *ms, u_char *sec0, int len __unused)
  99 {
 100         int i, error;
 101         off_t l[NDOSPART];
 102         struct dos_partition ndp[NDOSPART], *dp;
 103         MD5_CTX md5sum;
 104
 105         g_topology_assert();
 106
 107         if (sec0[0x1fe] != 0x55 && sec0[0x1ff] != 0xaa)
 108                 return (EBUSY);
 109
 110         dp = ndp;
 111         for (i = 0; i < NDOSPART; i++) {
 112                 dos_partition_dec(
 113                     sec0 + DOSPARTOFF + i * sizeof(struct dos_partition),
 114                     dp + i);
 115         }
 116         if ((!bcmp(dp, historical_bogus_partition_table,
 117             sizeof historical_bogus_partition_table)) ||
 118             (!bcmp(dp, historical_bogus_partition_table_fixed,
 119             sizeof historical_bogus_partition_table_fixed))) {
 120                 /*
 121                  * We will not allow people to write these from "the inside",
 122                  * Since properly selfdestructing takes too much code.  If
 123                  * people really want to do this, they cannot have any
 124                  * providers of this geom open, and in that case they can just
 125                  * as easily overwrite the MBR in the parent device.
 126                  */
 127                 return(EBUSY);
 128         }
 129         for (i = 0; i < NDOSPART; i++) {
 130                 /*
 131                  * A Protective MBR (PMBR) has a single partition of
 132                  * type 0xEE spanning the whole disk. Such a MBR
 133                  * protects a GPT on the disk from MBR tools that
 134                  * don't know anything about GPT. We're interpreting
 135                  * it a bit more loosely: any partition of type 0xEE
 136                  * is to be skipped as it doesn't contain any data
 137                  * that we should care about. We still allow other
 138                  * partitions to be present in the MBR. A PMBR will
 139                  * be handled correctly anyway.
 140                  */
 141                 if (dp[i].dp_typ == DOSPTYP_PMBR)
 142                         l[i] = 0;
 143                 else if (dp[i].dp_flag != 0 && dp[i].dp_flag != 0x80)
 144                         l[i] = 0;
 145                 else if (dp[i].dp_typ == 0)
 146                         l[i] = 0;
 147                 else
 148                         l[i] = (off_t)dp[i].dp_size * ms->sectorsize;
 149                 error = g_slice_config(gp, i, G_SLICE_CONFIG_CHECK,
 150                     (off_t)dp[i].dp_start * ms->sectorsize, l[i],
 151                     ms->sectorsize, "%ss%d", gp->name, 1 + i);
 152                 if (error)
 153                         return (error);
 154         }
 155         for (i = 0; i < NDOSPART; i++) {
 156                 ms->type[i] = dp[i].dp_typ;
 157                 g_slice_config(gp, i, G_SLICE_CONFIG_SET,
 158                     (off_t)dp[i].dp_start * ms->sectorsize, l[i],
 159                     ms->sectorsize, "%ss%d", gp->name, 1 + i);
 160         }
 161         bcopy(sec0, ms->sec0, 512);
 162
 163         /*
 164          * Calculate MD5 from the first sector and use it for avoiding
 165          * recursive slices creation.
 166          */
 167         MD5Init(&md5sum);
 168         MD5Update(&md5sum, ms->sec0, sizeof(ms->sec0));
 169         MD5Final(ms->slicesum, &md5sum);
 170
 171         return (0);
 172 }
 173
 174 static int
 175 g_mbr_ioctl(struct g_provider *pp, u_long cmd, void *data, int fflag, struct thread *td)
 176 {
 177         struct g_geom *gp;
 178         struct g_mbr_softc *ms;
 179         struct g_slicer *gsp;
 180         struct g_consumer *cp;
 181         int error, opened;
 182
 183         gp = pp->geom;
 184         gsp = gp->softc;
 185         ms = gsp->softc;
 186
 187         opened = 0;
 188         error = 0;
 189         switch(cmd) {
 190         case DIOCSMBR: {
 191                 if (!(fflag & FWRITE))
 192                         return (EPERM);
 193                 g_topology_lock();
 194                 cp = LIST_FIRST(&gp->consumer);
 195                 if (cp->acw == 0) {
 196                         error = g_access(cp, 0, 1, 0);
 197                         if (error == 0)
 198                                 opened = 1;
 199                 }
 200                 if (!error)
 201                         error = g_mbr_modify(gp, ms, data, 512);
 202                 if (!error)
 203                         error = g_write_data(cp, 0, data, 512);
 204                 if (opened)
 205                         g_access(cp, 0, -1 , 0);
 206                 g_topology_unlock();
 207                 return(error);
 208         }
 209         default:
 210                 return (ENOIOCTL);
 211         }
 212 }
 213
 214 static int
 215 g_mbr_start(struct bio *bp)
 216 {
 217         struct g_provider *pp;
 218         struct g_geom *gp;
 219         struct g_mbr_softc *mp;
 220         struct g_slicer *gsp;
 221         int idx;
 222
 223         pp = bp->bio_to;
 224         idx = pp->index;
 225         gp = pp->geom;
 226         gsp = gp->softc;
 227         mp = gsp->softc;
 228         if (bp->bio_cmd == BIO_GETATTR) {
 229                 if (g_handleattr_int(bp, "MBR::type", mp->type[idx]))
 230                         return (1);
 231                 if (g_handleattr_off_t(bp, "MBR::offset",
 232                     gsp->slices[idx].offset))
 233                         return (1);
 234                 if (g_handleattr(bp, "MBR::slicesum", mp->slicesum,
 235                     sizeof(mp->slicesum)))
 236                         return (1);
 237         }
 238
 239         return (0);
 240 }
 241
 242 static void
 243 g_mbr_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp)
 244 {
 245         struct g_mbr_softc *mp;
 246         struct g_slicer *gsp;
 247
 248         gsp = gp->softc;
 249         mp = gsp->softc;
 250         g_slice_dumpconf(sb, indent, gp, cp, pp);
 251         if (pp != NULL) {
 252                 if (indent == NULL)
 253                         sbuf_printf(sb, " ty %d", mp->type[pp->index]);
 254                 else
 255                         sbuf_printf(sb, "%s<type>%d</type>\n", indent,
 256                             mp->type[pp->index]);
 257         }
 258 }
 259
 260 static struct g_geom *
 261 g_mbr_taste(struct g_class *mp, struct g_provider *pp, int insist)
 262 {
 263         struct g_geom *gp;
 264         struct g_consumer *cp;
 265         int error;
 266         struct g_mbr_softc *ms;
 267         u_int fwsectors, sectorsize;
 268         u_char *buf;
 269         u_char hash[16];
 270         MD5_CTX md5sum;
 271
 272         g_trace(G_T_TOPOLOGY, "mbr_taste(%s,%s)", mp->name, pp->name);
 273         g_topology_assert();
 274         if (!strcmp(pp->geom->class->name, MBR_CLASS_NAME))
 275                 return (NULL);
 276         gp = g_slice_new(mp, NDOSPART, pp, &cp, &ms, sizeof *ms, g_mbr_start);
 277         if (gp == NULL)
 278                 return (NULL);
 279         g_topology_unlock();
 280         do {
 281                 error = g_getattr("GEOM::fwsectors", cp, &fwsectors);
 282                 if (error)
 283                         fwsectors = 17;
 284                 sectorsize = cp->provider->sectorsize;
 285                 if (sectorsize < 512)
 286                         break;
 287                 ms->sectorsize = sectorsize;
 288                 buf = g_read_data(cp, 0, sectorsize, NULL);
 289                 if (buf == NULL)
 290                         break;
 291
 292                 /*
 293                  * Calculate MD5 from the first sector and use it for avoiding
 294                  * recursive slices creation.
 295                  */
 296                 bcopy(buf, ms->sec0, 512);
 297                 MD5Init(&md5sum);
 298                 MD5Update(&md5sum, ms->sec0, sizeof(ms->sec0));
 299                 MD5Final(ms->slicesum, &md5sum);
 300
 301                 error = g_getattr("MBR::slicesum", cp, &hash);
 302                 if (!error && !bcmp(ms->slicesum, hash, sizeof(hash))) {
 303                         g_free(buf);
 304                         break;
 305                 }
 306
 307                 g_topology_lock();
 308                 g_mbr_modify(gp, ms, buf, 512);
 309                 g_topology_unlock();
 310                 g_free(buf);
 311                 break;
 312         } while (0);
 313         g_topology_lock();
 314         g_access(cp, -1, 0, 0);
 315         if (LIST_EMPTY(&gp->provider)) {
 316                 g_slice_spoiled(cp);
 317                 return (NULL);
 318         }
 319         return (gp);
 320 }
 321
 322 static void
 323 g_mbr_config(struct gctl_req *req, struct g_class *mp, const char *verb)
 324 {
 325         struct g_geom *gp;
 326         struct g_consumer *cp;
 327         struct g_mbr_softc *ms;
 328         struct g_slicer *gsp;
 329         int opened = 0, error = 0;
 330         void *data;
 331         int len;
 332
 333         g_topology_assert();
 334         gp = gctl_get_geom(req, mp, "geom");
 335         if (gp == NULL)
 336                 return;
 337         if (strcmp(verb, "write MBR")) {
 338                 gctl_error(req, "Unknown verb");
 339                 return;
 340         }
 341         gsp = gp->softc;
 342         ms = gsp->softc;
 343         data = gctl_get_param(req, "data", &len);
 344         if (data == NULL)
 345                 return;
 346         if (len < 512 || (len % 512)) {
 347                 gctl_error(req, "Wrong request length");
 348                 return;
 349         }
 350         cp = LIST_FIRST(&gp->consumer);
 351         if (cp->acw == 0) {
 352                 error = g_access(cp, 0, 1, 0);
 353                 if (error == 0)
 354                         opened = 1;
 355         }
 356         if (!error)
 357                 error = g_mbr_modify(gp, ms, data, len);
 358         if (error)
 359                 gctl_error(req, "conflict with open slices");
 360         if (!error)
 361                 error = g_write_data(cp, 0, data, len);
 362         if (error)
 363                 gctl_error(req, "sector zero write failed");
 364         if (opened)
 365                 g_access(cp, 0, -1 , 0);
 366         return;
 367 }
 368
 369 static struct g_class g_mbr_class       = {
 370         .name = MBR_CLASS_NAME,
 371         .version = G_VERSION,
 372         .taste = g_mbr_taste,
 373         .dumpconf = g_mbr_dumpconf,
 374         .ctlreq = g_mbr_config,
 375         .ioctl = g_mbr_ioctl,
 376 };
 377
 378 DECLARE_GEOM_CLASS(g_mbr_class, g_mbr);
 379
 380 #define NDOSEXTPART             32
 381 struct g_mbrext_softc {
 382         int             type [NDOSEXTPART];
 383 };
 384
 385 static int
 386 g_mbrext_start(struct bio *bp)
 387 {
 388         struct g_provider *pp;
 389         struct g_geom *gp;
 390         struct g_mbrext_softc *mp;
 391         struct g_slicer *gsp;
 392         int idx;
 393
 394         pp = bp->bio_to;
 395         idx = pp->index;
 396         gp = pp->geom;
 397         gsp = gp->softc;
 398         mp = gsp->softc;
 399         if (bp->bio_cmd == BIO_GETATTR) {
 400                 if (g_handleattr_int(bp, "MBR::type", mp->type[idx]))
 401                         return (1);
 402         }
 403         return (0);
 404 }
 405
 406 static void
 407 g_mbrext_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp)
 408 {
 409         struct g_mbrext_softc *mp;
 410         struct g_slicer *gsp;
 411
 412         g_slice_dumpconf(sb, indent, gp, cp, pp);
 413         gsp = gp->softc;
 414         mp = gsp->softc;
 415         if (pp != NULL) {
 416                 if (indent == NULL)
 417                         sbuf_printf(sb, " ty %d", mp->type[pp->index]);
 418                 else
 419                         sbuf_printf(sb, "%s<type>%d</type>\n", indent,
 420                             mp->type[pp->index]);
 421         }
 422 }
 423
 424 static struct g_geom *
 425 g_mbrext_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
 426 {
 427         struct g_geom *gp;
 428         struct g_consumer *cp;
 429         int error, i, slice;
 430         struct g_mbrext_softc *ms;
 431         off_t off;
 432         u_char *buf;
 433         struct dos_partition dp[4];
 434         u_int fwsectors, sectorsize;
 435
 436         g_trace(G_T_TOPOLOGY, "g_mbrext_taste(%s,%s)", mp->name, pp->name);
 437         g_topology_assert();
 438         if (strcmp(pp->geom->class->name, MBR_CLASS_NAME))
 439                 return (NULL);
 440         gp = g_slice_new(mp, NDOSEXTPART, pp, &cp, &ms, sizeof *ms,
 441             g_mbrext_start);
 442         if (gp == NULL)
 443                 return (NULL);
 444         g_topology_unlock();
 445         off = 0;
 446         slice = 0;
 447         do {
 448                 error = g_getattr("MBR::type", cp, &i);
 449                 if (error || (i != DOSPTYP_EXT && i != DOSPTYP_EXTLBA))
 450                         break;
 451                 error = g_getattr("GEOM::fwsectors", cp, &fwsectors);
 452                 if (error)
 453                         fwsectors = 17;
 454                 sectorsize = cp->provider->sectorsize;
 455                 if (sectorsize != 512)
 456                         break;
 457                 for (;;) {
 458                         buf = g_read_data(cp, off, sectorsize, NULL);
 459                         if (buf == NULL)
 460                                 break;
 461                         if (buf[0x1fe] != 0x55 && buf[0x1ff] != 0xaa) {
 462                                 g_free(buf);
 463                                 break;
 464                         }
 465                         for (i = 0; i < NDOSPART; i++)
 466                                 dos_partition_dec(
 467                                     buf + DOSPARTOFF +
 468                                     i * sizeof(struct dos_partition), dp + i);
 469                         g_free(buf);
 470                         if (0 && bootverbose) {
 471                                 printf("MBREXT Slice %d on %s:\n",
 472                                     slice + 5, gp->name);
 473                                 g_mbr_print(0, dp);
 474                                 g_mbr_print(1, dp + 1);
 475                         }
 476                         if ((dp[0].dp_flag & 0x7f) == 0 &&
 477                              dp[0].dp_size != 0 && dp[0].dp_typ != 0) {
 478                                 g_topology_lock();
 479                                 g_slice_config(gp, slice, G_SLICE_CONFIG_SET,
 480                                     (((off_t)dp[0].dp_start) << 9ULL) + off,
 481                                     ((off_t)dp[0].dp_size) << 9ULL,
 482                                     sectorsize,
 483                                     "%*.*s%d",
 484                                     (int)strlen(gp->name) - 1,
 485                                     (int)strlen(gp->name) - 1,
 486                                     gp->name,
 487                                     slice + 5);
 488                                 g_topology_unlock();
 489                                 ms->type[slice] = dp[0].dp_typ;
 490                                 slice++;
 491                         }
 492                         if (dp[1].dp_flag != 0)
 493                                 break;
 494                         if (dp[1].dp_typ != DOSPTYP_EXT &&
 495                             dp[1].dp_typ != DOSPTYP_EXTLBA)
 496                                 break;
 497                         if (dp[1].dp_size == 0)
 498                                 break;
 499                         off = ((off_t)dp[1].dp_start) << 9ULL;
 500                 }
 501                 break;
 502         } while (0);
 503         g_topology_lock();
 504         g_access(cp, -1, 0, 0);
 505         if (LIST_EMPTY(&gp->provider)) {
 506                 g_slice_spoiled(cp);
 507                 return (NULL);
 508         }
 509         return (gp);
 510 }
 511
 512
 513 static struct g_class g_mbrext_class    = {
 514         .name = MBREXT_CLASS_NAME,
 515         .version = G_VERSION,
 516         .taste = g_mbrext_taste,
 517         .dumpconf = g_mbrext_dumpconf,
 518 };
 519
 520 DECLARE_GEOM_CLASS(g_mbrext_class, g_mbrext);