The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/geom/geom_mbr.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    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: releng/6.4/sys/geom/geom_mbr.c 153827 2005-12-29 05:59:51Z sobomax $");
   35 
   36 #include <sys/param.h>
   37 #include <sys/errno.h>
   38 #include <sys/endian.h>
   39 #include <sys/systm.h>
   40 #include <sys/kernel.h>
   41 #include <sys/fcntl.h>
   42 #include <sys/malloc.h>
   43 #include <sys/bio.h>
   44 #include <sys/lock.h>
   45 #include <sys/mutex.h>
   46 #include <sys/md5.h>
   47 
   48 #include <sys/diskmbr.h>
   49 #include <sys/sbuf.h>
   50 #include <geom/geom.h>
   51 #include <geom/geom_slice.h>
   52 
   53 #define MBR_CLASS_NAME "MBR"
   54 #define MBREXT_CLASS_NAME "MBREXT"
   55 
   56 static struct dos_partition historical_bogus_partition_table[NDOSPART] = {
   57         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
   58         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
   59         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
   60         { 0x80, 0, 1, 0, DOSPTYP_386BSD, 255, 255, 255, 0, 50000, },
   61 };
   62 
   63 static struct dos_partition historical_bogus_partition_table_fixed[NDOSPART] = {
   64         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
   65         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
   66         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
   67         { 0x80, 0, 1, 0, DOSPTYP_386BSD, 254, 255, 255, 0, 50000, },
   68 };
   69 
   70 static void
   71 g_mbr_print(int i, struct dos_partition *dp)
   72 {
   73 
   74         printf("[%d] f:%02x typ:%d", i, dp->dp_flag, dp->dp_typ);
   75         printf(" s(CHS):%d/%d/%d", DPCYL(dp->dp_scyl, dp->dp_ssect),
   76             dp->dp_shd, DPSECT(dp->dp_ssect));
   77         printf(" e(CHS):%d/%d/%d", DPCYL(dp->dp_ecyl, dp->dp_esect),
   78             dp->dp_ehd, DPSECT(dp->dp_esect));
   79         printf(" s:%d l:%d\n", dp->dp_start, dp->dp_size);
   80 }
   81 
   82 struct g_mbr_softc {
   83         int             type [NDOSPART];
   84         u_int           sectorsize;
   85         u_char          sec0[512];
   86         u_char          slicesum[16];
   87 };
   88 
   89 /*
   90  * XXX: Add gctl_req arg and give good error msgs.
   91  * XXX: Check that length argument does not bring boot code inside any slice.
   92  */
   93 static int
   94 g_mbr_modify(struct g_geom *gp, struct g_mbr_softc *ms, u_char *sec0, int len __unused)
   95 {
   96         int i, error;
   97         off_t l[NDOSPART];
   98         struct dos_partition ndp[NDOSPART], *dp;
   99         MD5_CTX md5sum;
  100 
  101         g_topology_assert();
  102 
  103         if (sec0[0x1fe] != 0x55 && sec0[0x1ff] != 0xaa)
  104                 return (EBUSY);
  105 
  106         dp = ndp;
  107         for (i = 0; i < NDOSPART; i++) {
  108                 dos_partition_dec(
  109                     sec0 + DOSPARTOFF + i * sizeof(struct dos_partition),
  110                     dp + i);
  111         }
  112         if ((!bcmp(dp, historical_bogus_partition_table,
  113             sizeof historical_bogus_partition_table)) ||
  114             (!bcmp(dp, historical_bogus_partition_table_fixed,
  115             sizeof historical_bogus_partition_table_fixed))) {
  116                 /*
  117                  * We will not allow people to write these from "the inside",
  118                  * Since properly selfdestructing takes too much code.  If 
  119                  * people really want to do this, they cannot have any
  120                  * providers of this geom open, and in that case they can just
  121                  * as easily overwrite the MBR in the parent device.
  122                  */
  123                 return(EBUSY);
  124         }
  125         for (i = 0; i < NDOSPART; i++) {
  126                 /* 
  127                  * A Protective MBR (PMBR) has a single partition of
  128                  * type 0xEE spanning the whole disk. Such a MBR
  129                  * protects a GPT on the disk from MBR tools that
  130                  * don't know anything about GPT. We're interpreting
  131                  * it a bit more loosely: any partition of type 0xEE
  132                  * is to be skipped as it doesn't contain any data
  133                  * that we should care about. We still allow other
  134                  * partitions to be present in the MBR. A PMBR will
  135                  * be handled correctly anyway.
  136                  */
  137                 if (dp[i].dp_typ == DOSPTYP_PMBR)
  138                         l[i] = 0;
  139                 else if (dp[i].dp_flag != 0 && dp[i].dp_flag != 0x80)
  140                         l[i] = 0;
  141                 else if (dp[i].dp_typ == 0)
  142                         l[i] = 0;
  143                 else
  144                         l[i] = (off_t)dp[i].dp_size * ms->sectorsize;
  145                 error = g_slice_config(gp, i, G_SLICE_CONFIG_CHECK,
  146                     (off_t)dp[i].dp_start * ms->sectorsize, l[i],
  147                     ms->sectorsize, "%ss%d", gp->name, 1 + i);
  148                 if (error)
  149                         return (error);
  150         }
  151         for (i = 0; i < NDOSPART; i++) {
  152                 ms->type[i] = dp[i].dp_typ;
  153                 g_slice_config(gp, i, G_SLICE_CONFIG_SET,
  154                     (off_t)dp[i].dp_start * ms->sectorsize, l[i],
  155                     ms->sectorsize, "%ss%d", gp->name, 1 + i);
  156         }
  157         bcopy(sec0, ms->sec0, 512);
  158 
  159         /*
  160          * Calculate MD5 from the first sector and use it for avoiding
  161          * recursive slices creation.
  162          */
  163         MD5Init(&md5sum);
  164         MD5Update(&md5sum, ms->sec0, sizeof(ms->sec0));
  165         MD5Final(ms->slicesum, &md5sum);
  166 
  167         return (0);
  168 }
  169 
  170 static int
  171 g_mbr_ioctl(struct g_provider *pp, u_long cmd, void *data, int fflag, struct thread *td)
  172 {
  173         struct g_geom *gp;
  174         struct g_mbr_softc *ms;
  175         struct g_slicer *gsp;
  176         struct g_consumer *cp;
  177         int error, opened;
  178 
  179         gp = pp->geom;
  180         gsp = gp->softc;
  181         ms = gsp->softc;
  182 
  183         opened = 0;
  184         error = 0;
  185         switch(cmd) {
  186         case DIOCSMBR: {
  187                 if (!(fflag & FWRITE))
  188                         return (EPERM);
  189                 DROP_GIANT();
  190                 g_topology_lock();
  191                 cp = LIST_FIRST(&gp->consumer);
  192                 if (cp->acw == 0) {
  193                         error = g_access(cp, 0, 1, 0);
  194                         if (error == 0)
  195                                 opened = 1;
  196                 }
  197                 if (!error)
  198                         error = g_mbr_modify(gp, ms, data, 512);
  199                 if (!error)
  200                         error = g_write_data(cp, 0, data, 512);
  201                 if (opened)
  202                         g_access(cp, 0, -1 , 0);
  203                 g_topology_unlock();
  204                 PICKUP_GIANT();
  205                 return(error);
  206         }
  207         default:
  208                 return (ENOIOCTL);
  209         }
  210 }
  211 
  212 static int
  213 g_mbr_start(struct bio *bp)
  214 {
  215         struct g_provider *pp;
  216         struct g_geom *gp;
  217         struct g_mbr_softc *mp;
  218         struct g_slicer *gsp;
  219         int idx;
  220 
  221         pp = bp->bio_to;
  222         idx = pp->index;
  223         gp = pp->geom;
  224         gsp = gp->softc;
  225         mp = gsp->softc;
  226         if (bp->bio_cmd == BIO_GETATTR) {
  227                 if (g_handleattr_int(bp, "MBR::type", mp->type[idx]))
  228                         return (1);
  229                 if (g_handleattr_off_t(bp, "MBR::offset",
  230                     gsp->slices[idx].offset))
  231                         return (1);
  232                 if (g_handleattr(bp, "MBR::slicesum", mp->slicesum,
  233                     sizeof(mp->slicesum)))
  234                         return (1);
  235         }
  236 
  237         return (0);
  238 }
  239 
  240 static void
  241 g_mbr_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp)
  242 {
  243         struct g_mbr_softc *mp;
  244         struct g_slicer *gsp;
  245 
  246         gsp = gp->softc;
  247         mp = gsp->softc;
  248         g_slice_dumpconf(sb, indent, gp, cp, pp);
  249         if (pp != NULL) {
  250                 if (indent == NULL)
  251                         sbuf_printf(sb, " ty %d", mp->type[pp->index]);
  252                 else
  253                         sbuf_printf(sb, "%s<type>%d</type>\n", indent,
  254                             mp->type[pp->index]);
  255         }
  256 }
  257 
  258 static struct g_geom *
  259 g_mbr_taste(struct g_class *mp, struct g_provider *pp, int insist)
  260 {
  261         struct g_geom *gp;
  262         struct g_consumer *cp;
  263         int error;
  264         struct g_mbr_softc *ms;
  265         u_int fwsectors, sectorsize;
  266         u_char *buf;
  267         u_char hash[16];
  268         MD5_CTX md5sum;
  269 
  270         g_trace(G_T_TOPOLOGY, "mbr_taste(%s,%s)", mp->name, pp->name);
  271         g_topology_assert();
  272         if (!strcmp(pp->geom->class->name, MBR_CLASS_NAME))
  273                 return (NULL);
  274         gp = g_slice_new(mp, NDOSPART, pp, &cp, &ms, sizeof *ms, g_mbr_start);
  275         if (gp == NULL)
  276                 return (NULL);
  277         g_topology_unlock();
  278         do {
  279                 error = g_getattr("GEOM::fwsectors", cp, &fwsectors);
  280                 if (error)
  281                         fwsectors = 17;
  282                 sectorsize = cp->provider->sectorsize;
  283                 if (sectorsize < 512)
  284                         break;
  285                 ms->sectorsize = sectorsize;
  286                 buf = g_read_data(cp, 0, sectorsize, NULL);
  287                 if (buf == NULL)
  288                         break;
  289 
  290                 /*
  291                  * Calculate MD5 from the first sector and use it for avoiding
  292                  * recursive slices creation.
  293                  */
  294                 bcopy(buf, ms->sec0, 512);
  295                 MD5Init(&md5sum);
  296                 MD5Update(&md5sum, ms->sec0, sizeof(ms->sec0));
  297                 MD5Final(ms->slicesum, &md5sum);
  298 
  299                 error = g_getattr("MBR::slicesum", cp, &hash);
  300                 if (!error && !bcmp(ms->slicesum, hash, sizeof(hash))) {
  301                         g_free(buf);
  302                         break;
  303                 }
  304 
  305                 g_topology_lock();
  306                 g_mbr_modify(gp, ms, buf, 512);
  307                 g_topology_unlock();
  308                 g_free(buf);
  309                 break;
  310         } while (0);
  311         g_topology_lock();
  312         g_access(cp, -1, 0, 0);
  313         if (LIST_EMPTY(&gp->provider)) {
  314                 g_slice_spoiled(cp);
  315                 return (NULL);
  316         }
  317         return (gp);
  318 }
  319 
  320 static void
  321 g_mbr_config(struct gctl_req *req, struct g_class *mp, const char *verb)
  322 {
  323         struct g_geom *gp;
  324         struct g_consumer *cp;
  325         struct g_mbr_softc *ms;
  326         struct g_slicer *gsp;
  327         int opened = 0, error = 0;
  328         void *data;
  329         int len;
  330 
  331         g_topology_assert();
  332         gp = gctl_get_geom(req, mp, "geom");
  333         if (gp == NULL)
  334                 return;
  335         if (strcmp(verb, "write MBR")) {
  336                 gctl_error(req, "Unknown verb");
  337                 return;
  338         }
  339         gsp = gp->softc;
  340         ms = gsp->softc;
  341         data = gctl_get_param(req, "data", &len);
  342         if (data == NULL)
  343                 return;
  344         if (len < 512 || (len % 512)) {
  345                 gctl_error(req, "Wrong request length");
  346                 return;
  347         }
  348         cp = LIST_FIRST(&gp->consumer);
  349         if (cp->acw == 0) {
  350                 error = g_access(cp, 0, 1, 0);
  351                 if (error == 0)
  352                         opened = 1;
  353         }
  354         if (!error)
  355                 error = g_mbr_modify(gp, ms, data, len);
  356         if (error)
  357                 gctl_error(req, "conflict with open slices");
  358         if (!error)
  359                 error = g_write_data(cp, 0, data, len);
  360         if (error)
  361                 gctl_error(req, "sector zero write failed");
  362         if (opened)
  363                 g_access(cp, 0, -1 , 0);
  364         return;
  365 }
  366 
  367 static struct g_class g_mbr_class       = {
  368         .name = MBR_CLASS_NAME,
  369         .version = G_VERSION,
  370         .taste = g_mbr_taste,
  371         .dumpconf = g_mbr_dumpconf,
  372         .ctlreq = g_mbr_config,
  373         .ioctl = g_mbr_ioctl,
  374 };
  375 
  376 DECLARE_GEOM_CLASS(g_mbr_class, g_mbr);
  377 
  378 #define NDOSEXTPART             32
  379 struct g_mbrext_softc {
  380         int             type [NDOSEXTPART];
  381 };
  382 
  383 static int
  384 g_mbrext_start(struct bio *bp)
  385 {
  386         struct g_provider *pp;
  387         struct g_geom *gp;
  388         struct g_mbrext_softc *mp;
  389         struct g_slicer *gsp;
  390         int idx;
  391 
  392         pp = bp->bio_to;
  393         idx = pp->index;
  394         gp = pp->geom;
  395         gsp = gp->softc;
  396         mp = gsp->softc;
  397         if (bp->bio_cmd == BIO_GETATTR) {
  398                 if (g_handleattr_int(bp, "MBR::type", mp->type[idx]))
  399                         return (1);
  400         }
  401         return (0);
  402 }
  403 
  404 static void
  405 g_mbrext_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp)
  406 {
  407         struct g_mbrext_softc *mp;
  408         struct g_slicer *gsp;
  409 
  410         g_slice_dumpconf(sb, indent, gp, cp, pp);
  411         gsp = gp->softc;
  412         mp = gsp->softc;
  413         if (pp != NULL) {
  414                 if (indent == NULL)
  415                         sbuf_printf(sb, " ty %d", mp->type[pp->index]);
  416                 else
  417                         sbuf_printf(sb, "%s<type>%d</type>\n", indent,
  418                             mp->type[pp->index]);
  419         }
  420 }
  421 
  422 static struct g_geom *
  423 g_mbrext_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
  424 {
  425         struct g_geom *gp;
  426         struct g_consumer *cp;
  427         int error, i, slice;
  428         struct g_mbrext_softc *ms;
  429         off_t off;
  430         u_char *buf;
  431         struct dos_partition dp[4];
  432         u_int fwsectors, sectorsize;
  433 
  434         g_trace(G_T_TOPOLOGY, "g_mbrext_taste(%s,%s)", mp->name, pp->name);
  435         g_topology_assert();
  436         if (strcmp(pp->geom->class->name, MBR_CLASS_NAME))
  437                 return (NULL);
  438         gp = g_slice_new(mp, NDOSEXTPART, pp, &cp, &ms, sizeof *ms,
  439             g_mbrext_start);
  440         if (gp == NULL)
  441                 return (NULL);
  442         g_topology_unlock();
  443         off = 0;
  444         slice = 0;
  445         do {
  446                 error = g_getattr("MBR::type", cp, &i);
  447                 if (error || (i != DOSPTYP_EXT && i != DOSPTYP_EXTLBA))
  448                         break;
  449                 error = g_getattr("GEOM::fwsectors", cp, &fwsectors);
  450                 if (error)
  451                         fwsectors = 17;
  452                 sectorsize = cp->provider->sectorsize;
  453                 if (sectorsize != 512)
  454                         break;
  455                 for (;;) {
  456                         buf = g_read_data(cp, off, sectorsize, NULL);
  457                         if (buf == NULL)
  458                                 break;
  459                         if (buf[0x1fe] != 0x55 && buf[0x1ff] != 0xaa) {
  460                                 g_free(buf);
  461                                 break;
  462                         }
  463                         for (i = 0; i < NDOSPART; i++) 
  464                                 dos_partition_dec(
  465                                     buf + DOSPARTOFF + 
  466                                     i * sizeof(struct dos_partition), dp + i);
  467                         g_free(buf);
  468                         if (0 && bootverbose) {
  469                                 printf("MBREXT Slice %d on %s:\n",
  470                                     slice + 5, gp->name);
  471                                 g_mbr_print(0, dp);
  472                                 g_mbr_print(1, dp + 1);
  473                         }
  474                         if ((dp[0].dp_flag & 0x7f) == 0 &&
  475                              dp[0].dp_size != 0 && dp[0].dp_typ != 0) {
  476                                 g_topology_lock();
  477                                 g_slice_config(gp, slice, G_SLICE_CONFIG_SET,
  478                                     (((off_t)dp[0].dp_start) << 9ULL) + off,
  479                                     ((off_t)dp[0].dp_size) << 9ULL,
  480                                     sectorsize,
  481                                     "%*.*s%d",
  482                                     strlen(gp->name) - 1,
  483                                     strlen(gp->name) - 1,
  484                                     gp->name,
  485                                     slice + 5);
  486                                 g_topology_unlock();
  487                                 ms->type[slice] = dp[0].dp_typ;
  488                                 slice++;
  489                         }
  490                         if (dp[1].dp_flag != 0)
  491                                 break;
  492                         if (dp[1].dp_typ != DOSPTYP_EXT &&
  493                             dp[1].dp_typ != DOSPTYP_EXTLBA)
  494                                 break;
  495                         if (dp[1].dp_size == 0)
  496                                 break;
  497                         off = ((off_t)dp[1].dp_start) << 9ULL;
  498                 }
  499                 break;
  500         } while (0);
  501         g_topology_lock();
  502         g_access(cp, -1, 0, 0);
  503         if (LIST_EMPTY(&gp->provider)) {
  504                 g_slice_spoiled(cp);
  505                 return (NULL);
  506         }
  507         return (gp);
  508 }
  509 
  510 
  511 static struct g_class g_mbrext_class    = {
  512         .name = MBREXT_CLASS_NAME,
  513         .version = G_VERSION,
  514         .taste = g_mbrext_taste,
  515         .dumpconf = g_mbrext_dumpconf,
  516 };
  517 
  518 DECLARE_GEOM_CLASS(g_mbrext_class, g_mbrext);

Cache object: 304e3a66ce8ed70f978922993cff163c


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.