usr/src/boot/sys/boot/common/gpt.c

   1 /*
   2  * Copyright (c) 2010 Pawel Jakub Dawidek <pjd@FreeBSD.org>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/cdefs.h>
  28
  29 #include <sys/param.h>
  30 #include <sys/gpt.h>
  31
  32 #ifndef LITTLE_ENDIAN
  33 #error gpt.c works only for little endian architectures
  34 #endif
  35
  36 #include "zlib.h"
  37 #include "drv.h"
  38 #include "util.h"
  39 #include "gpt.h"
  40
  41 #define MAXTBLENTS      128
  42
  43 static struct gpt_hdr hdr_primary, hdr_backup, *gpthdr;
  44 static uint64_t hdr_primary_lba, hdr_backup_lba;
  45 static struct gpt_ent table_primary[MAXTBLENTS], table_backup[MAXTBLENTS];
  46 static struct gpt_ent *gpttable;
  47 static int curent, bootonce;
  48
  49 /*
  50  * Buffer below 64kB passed on gptread(), which can hold at least
  51  * one sector of data (512 bytes).
  52  */
  53 static char *secbuf;
  54
  55 static void
  56 gptupdate(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
  57     struct gpt_ent *table)
  58 {
  59         int entries_per_sec, firstent;
  60         daddr_t slba;
  61
  62         /*
  63          * We need to update the following for both primary and backup GPT:
  64          * 1. Sector on disk that contains current partition.
  65          * 2. Partition table checksum.
  66          * 3. Header checksum.
  67          * 4. Header on disk.
  68          */
  69
  70         entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
  71         slba = curent / entries_per_sec;
  72         firstent = slba * entries_per_sec;
  73         bcopy(&table[firstent], secbuf, DEV_BSIZE);
  74         slba += hdr->hdr_lba_table;
  75         if (drvwrite(dskp, secbuf, slba, 1)) {
  76                 printf("%s: unable to update %s GPT partition table\n",
  77                     BOOTPROG, which);
  78                 return;
  79         }
  80         hdr->hdr_crc_table = crc32(0, Z_NULL, 0);
  81         hdr->hdr_crc_table = crc32(hdr->hdr_crc_table, table,
  82             hdr->hdr_entries * hdr->hdr_entsz);
  83         hdr->hdr_crc_self = crc32(0, Z_NULL, 0);
  84         hdr->hdr_crc_self = crc32(hdr->hdr_crc_self, hdr, hdr->hdr_size);
  85         bzero(secbuf, DEV_BSIZE);
  86         bcopy(hdr, secbuf, hdr->hdr_size);
  87         if (drvwrite(dskp, secbuf, hdr->hdr_lba_self, 1)) {
  88                 printf("%s: unable to update %s GPT header\n", BOOTPROG, which);
  89                 return;
  90         }
  91 }
  92
  93 int
  94 gptfind(const uuid_t *uuid, struct dsk *dskp, int part)
  95 {
  96         struct gpt_ent *ent;
  97         int firsttry;
  98
  99         if (part >= 0) {
 100                 if (part == 0 || part > gpthdr->hdr_entries) {
 101                         printf("%s: invalid partition index\n", BOOTPROG);
 102                         return (-1);
 103                 }
 104                 ent = &gpttable[part - 1];
 105                 if (bcmp(&ent->ent_type, uuid, sizeof (uuid_t)) != 0) {
 106                         printf("%s: specified partition is not UFS\n",
 107                             BOOTPROG);
 108                         return (-1);
 109                 }
 110                 curent = part - 1;
 111                 goto found;
 112         }
 113
 114         firsttry = (curent == -1);
 115         curent++;
 116         if (curent >= gpthdr->hdr_entries) {
 117                 curent = gpthdr->hdr_entries;
 118                 return (-1);
 119         }
 120         if (bootonce) {
 121                 /*
 122                  * First look for partition with both GPT_ENT_ATTR_BOOTME and
 123                  * GPT_ENT_ATTR_BOOTONCE flags.
 124                  */
 125                 for (; curent < gpthdr->hdr_entries; curent++) {
 126                         ent = &gpttable[curent];
 127                         if (bcmp(&ent->ent_type, uuid, sizeof (uuid_t)) != 0)
 128                                 continue;
 129                         if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTME))
 130                                 continue;
 131                         if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTONCE))
 132                                 continue;
 133                         /* Ok, found one. */
 134                         goto found;
 135                 }
 136                 bootonce = 0;
 137                 curent = 0;
 138         }
 139         for (; curent < gpthdr->hdr_entries; curent++) {
 140                 ent = &gpttable[curent];
 141                 if (bcmp(&ent->ent_type, uuid, sizeof (uuid_t)) != 0)
 142                         continue;
 143                 if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTME))
 144                         continue;
 145                 if (ent->ent_attr & GPT_ENT_ATTR_BOOTONCE)
 146                         continue;
 147                 /* Ok, found one. */
 148                 goto found;
 149         }
 150         if (firsttry) {
 151                 /*
 152                  * No partition with BOOTME flag was found, try to boot from
 153                  * first UFS partition.
 154                  */
 155                 for (curent = 0; curent < gpthdr->hdr_entries; curent++) {
 156                         ent = &gpttable[curent];
 157                         if (bcmp(&ent->ent_type, uuid, sizeof (uuid_t)) != 0)
 158                                 continue;
 159                         /* Ok, found one. */
 160                         goto found;
 161                 }
 162         }
 163         return (-1);
 164 found:
 165         dskp->part = curent + 1;
 166         ent = &gpttable[curent];
 167         dskp->start = ent->ent_lba_start;
 168         if (ent->ent_attr & GPT_ENT_ATTR_BOOTONCE) {
 169                 /*
 170                  * Clear BOOTME, but leave BOOTONCE set before trying to
 171                  * boot from this partition.
 172                  */
 173                 if (hdr_primary_lba > 0) {
 174                         table_primary[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTME;
 175                         gptupdate("primary", dskp, &hdr_primary, table_primary);
 176                 }
 177                 if (hdr_backup_lba > 0) {
 178                         table_backup[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTME;
 179                         gptupdate("backup", dskp, &hdr_backup, table_backup);
 180                 }
 181         }
 182         return (0);
 183 }
 184
 185 static int
 186 gptread_hdr(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
 187     uint64_t hdrlba)
 188 {
 189         uint32_t crc;
 190
 191         if (drvread(dskp, secbuf, hdrlba, 1)) {
 192                 printf("%s: unable to read %s GPT header\n", BOOTPROG, which);
 193                 return (-1);
 194         }
 195         bcopy(secbuf, hdr, sizeof (*hdr));
 196         if (bcmp(hdr->hdr_sig, GPT_HDR_SIG, sizeof (hdr->hdr_sig)) != 0 ||
 197             hdr->hdr_lba_self != hdrlba || hdr->hdr_revision < 0x00010000 ||
 198             hdr->hdr_entsz < sizeof (struct gpt_ent) ||
 199             hdr->hdr_entries > MAXTBLENTS || DEV_BSIZE % hdr->hdr_entsz != 0) {
 200                 printf("%s: invalid %s GPT header\n", BOOTPROG, which);
 201                 return (-1);
 202         }
 203         crc = hdr->hdr_crc_self;
 204         hdr->hdr_crc_self = crc32(0, Z_NULL, 0);
 205         if (crc32(hdr->hdr_crc_self, hdr, hdr->hdr_size) != crc) {
 206                 printf("%s: %s GPT header checksum mismatch\n", BOOTPROG,
 207                     which);
 208                 return (-1);
 209         }
 210         hdr->hdr_crc_self = crc;
 211         return (0);
 212 }
 213
 214 void
 215 gptbootfailed(struct dsk *dskp)
 216 {
 217
 218         if (!(gpttable[curent].ent_attr & GPT_ENT_ATTR_BOOTONCE))
 219                 return;
 220
 221         if (hdr_primary_lba > 0) {
 222                 table_primary[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
 223                 table_primary[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
 224                 gptupdate("primary", dskp, &hdr_primary, table_primary);
 225         }
 226         if (hdr_backup_lba > 0) {
 227                 table_backup[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
 228                 table_backup[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
 229                 gptupdate("backup", dskp, &hdr_backup, table_backup);
 230         }
 231 }
 232
 233 static void
 234 gptbootconv(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
 235     struct gpt_ent *table)
 236 {
 237         struct gpt_ent *ent;
 238         daddr_t slba;
 239         int table_updated, sector_updated;
 240         int entries_per_sec, nent, part;
 241
 242         table_updated = 0;
 243         entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
 244         for (nent = 0, slba = hdr->hdr_lba_table;
 245             slba < hdr->hdr_lba_table + hdr->hdr_entries / entries_per_sec;
 246             slba++, nent += entries_per_sec) {
 247                 sector_updated = 0;
 248                 for (part = 0; part < entries_per_sec; part++) {
 249                         ent = &table[nent + part];
 250                         if ((ent->ent_attr & (GPT_ENT_ATTR_BOOTME |
 251                             GPT_ENT_ATTR_BOOTONCE |
 252                             GPT_ENT_ATTR_BOOTFAILED)) !=
 253                             GPT_ENT_ATTR_BOOTONCE) {
 254                                 continue;
 255                         }
 256                         ent->ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
 257                         ent->ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
 258                         table_updated = 1;
 259                         sector_updated = 1;
 260                 }
 261                 if (!sector_updated)
 262                         continue;
 263                 bcopy(&table[nent], secbuf, DEV_BSIZE);
 264                 if (drvwrite(dskp, secbuf, slba, 1)) {
 265                         printf("%s: unable to update %s GPT partition table\n",
 266                             BOOTPROG, which);
 267                 }
 268         }
 269         if (!table_updated)
 270                 return;
 271         hdr->hdr_crc_table = crc32(0, Z_NULL, 0);
 272         hdr->hdr_crc_table = crc32(hdr->hdr_crc_table, table,
 273             hdr->hdr_entries * hdr->hdr_entsz);
 274         hdr->hdr_crc_self = crc32(0, Z_NULL, 0);
 275         hdr->hdr_crc_self = crc32(hdr->hdr_crc_self, hdr, hdr->hdr_size);
 276         bzero(secbuf, DEV_BSIZE);
 277         bcopy(hdr, secbuf, hdr->hdr_size);
 278         if (drvwrite(dskp, secbuf, hdr->hdr_lba_self, 1))
 279                 printf("%s: unable to update %s GPT header\n", BOOTPROG, which);
 280 }
 281
 282 static int
 283 gptread_table(const char *which, const uuid_t *uuid, struct dsk *dskp,
 284     struct gpt_hdr *hdr, struct gpt_ent *table)
 285 {
 286         struct gpt_ent *ent;
 287         int entries_per_sec;
 288         int part, nent;
 289         daddr_t slba;
 290
 291         if (hdr->hdr_entries == 0)
 292                 return (0);
 293
 294         entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
 295         slba = hdr->hdr_lba_table;
 296         nent = 0;
 297         for (;;) {
 298                 if (drvread(dskp, secbuf, slba, 1)) {
 299                         printf("%s: unable to read %s GPT partition table\n",
 300                             BOOTPROG, which);
 301                         return (-1);
 302                 }
 303                 ent = (struct gpt_ent *)secbuf;
 304                 for (part = 0; part < entries_per_sec; part++, ent++) {
 305                         bcopy(ent, &table[nent], sizeof (table[nent]));
 306                         if (++nent >= hdr->hdr_entries)
 307                                 break;
 308                 }
 309                 if (nent >= hdr->hdr_entries)
 310                         break;
 311                 slba++;
 312         }
 313         if (crc32(0, table, nent * hdr->hdr_entsz) != hdr->hdr_crc_table) {
 314                 printf("%s: %s GPT table checksum mismatch\n", BOOTPROG, which);
 315                 return (-1);
 316         }
 317         return (0);
 318 }
 319
 320 int
 321 gptread(const uuid_t *uuid, struct dsk *dskp, char *buf)
 322 {
 323         uint64_t altlba;
 324
 325         /*
 326          * Read and verify both GPT headers: primary and backup.
 327          */
 328
 329         secbuf = buf;
 330         hdr_primary_lba = hdr_backup_lba = 0;
 331         curent = -1;
 332         bootonce = 1;
 333         dskp->start = 0;
 334
 335         if (gptread_hdr("primary", dskp, &hdr_primary, 1) == 0 &&
 336             gptread_table("primary", uuid, dskp, &hdr_primary,
 337             table_primary) == 0) {
 338                 hdr_primary_lba = hdr_primary.hdr_lba_self;
 339                 gpthdr = &hdr_primary;
 340                 gpttable = table_primary;
 341         }
 342
 343         if (hdr_primary_lba > 0) {
 344                 /*
 345                  * If primary header is valid, we can get backup
 346                  * header location from there.
 347                  */
 348                 altlba = hdr_primary.hdr_lba_alt;
 349         } else {
 350                 altlba = drvsize(dskp);
 351                 if (altlba > 0)
 352                         altlba--;
 353         }
 354         if (altlba == 0)
 355                 printf("%s: unable to locate backup GPT header\n", BOOTPROG);
 356         else if (gptread_hdr("backup", dskp, &hdr_backup, altlba) == 0 &&
 357             gptread_table("backup", uuid, dskp, &hdr_backup,
 358             table_backup) == 0) {
 359                 hdr_backup_lba = hdr_backup.hdr_lba_self;
 360                 if (hdr_primary_lba == 0) {
 361                         gpthdr = &hdr_backup;
 362                         gpttable = table_backup;
 363                         printf("%s: using backup GPT\n", BOOTPROG);
 364                 }
 365         }
 366
 367         /*
 368          * Convert all BOOTONCE without BOOTME flags into BOOTFAILED.
 369          * BOOTONCE without BOOTME means that we tried to boot from it,
 370          * but failed after leaving gptboot and machine was rebooted.
 371          * We don't want to leave partitions marked as BOOTONCE only,
 372          * because when we boot successfully start-up scripts should
 373          * find at most one partition with only BOOTONCE flag and this
 374          * will mean that we booted from that partition.
 375          */
 376         if (hdr_primary_lba != 0)
 377                 gptbootconv("primary", dskp, &hdr_primary, table_primary);
 378         if (hdr_backup_lba != 0)
 379                 gptbootconv("backup", dskp, &hdr_backup, table_backup);
 380
 381         if (hdr_primary_lba == 0 && hdr_backup_lba == 0)
 382                 return (-1);
 383         return (0);
 384 }