stand/libsa/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 __FBSDID("$FreeBSD$");
  29
  30 #include <sys/param.h>
  31 #include <sys/gpt.h>
  32
  33 #ifndef LITTLE_ENDIAN
  34 #error gpt.c works only for little endian architectures
  35 #endif
  36
  37 #include "stand.h"
  38 #include "crc32.h"
  39 #include "drv.h"
  40 #include "gpt.h"
  41
  42 static struct gpt_hdr hdr_primary, hdr_backup, *gpthdr;
  43 static uint64_t hdr_primary_lba, hdr_backup_lba;
  44 static struct gpt_ent table_primary[MAXTBLENTS], table_backup[MAXTBLENTS];
  45 static struct gpt_ent *gpttable;
  46 static int curent, bootonce;
  47
  48 /*
  49  * Buffer below 64kB passed on gptread(), which can hold at least
  50  * one sector of data (512 bytes).
  51  */
  52 static char *secbuf;
  53
  54 static void
  55 gptupdate(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
  56     struct gpt_ent *table)
  57 {
  58         int entries_per_sec, firstent;
  59         daddr_t slba;
  60
  61         /*
  62          * We need to update the following for both primary and backup GPT:
  63          * 1. Sector on disk that contains current partition.
  64          * 2. Partition table checksum.
  65          * 3. Header checksum.
  66          * 4. Header on disk.
  67          */
  68
  69         entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
  70         slba = curent / entries_per_sec;
  71         firstent = slba * entries_per_sec;
  72         bcopy(&table[firstent], secbuf, DEV_BSIZE);
  73         slba += hdr->hdr_lba_table;
  74         if (drvwrite(dskp, secbuf, slba, 1)) {
  75                 printf("%s: unable to update %s GPT partition table\n",
  76                     BOOTPROG, which);
  77                 return;
  78         }
  79         hdr->hdr_crc_table = crc32(table, hdr->hdr_entries * hdr->hdr_entsz);
  80         hdr->hdr_crc_self = 0;
  81         hdr->hdr_crc_self = crc32(hdr, hdr->hdr_size);
  82         bzero(secbuf, DEV_BSIZE);
  83         bcopy(hdr, secbuf, hdr->hdr_size);
  84         if (drvwrite(dskp, secbuf, hdr->hdr_lba_self, 1)) {
  85                 printf("%s: unable to update %s GPT header\n", BOOTPROG, which);
  86                 return;
  87         }
  88 }
  89
  90 int
  91 gptfind(const uuid_t *uuid, struct dsk *dskp, int part)
  92 {
  93         struct gpt_ent *ent;
  94         int firsttry;
  95
  96         if (part >= 0) {
  97                 if (part == 0 || part > gpthdr->hdr_entries) {
  98                         printf("%s: invalid partition index\n", BOOTPROG);
  99                         return (-1);
 100                 }
 101                 ent = &gpttable[part - 1];
 102                 if (bcmp(&ent->ent_type, uuid, sizeof(uuid_t)) != 0) {
 103                         printf("%s: specified partition is not UFS\n",
 104                             BOOTPROG);
 105                         return (-1);
 106                 }
 107                 curent = part - 1;
 108                 goto found;
 109         }
 110
 111         firsttry = (curent == -1);
 112         curent++;
 113         if (curent >= gpthdr->hdr_entries) {
 114                 curent = gpthdr->hdr_entries;
 115                 return (-1);
 116         }
 117         if (bootonce) {
 118                 /*
 119                  * First look for partition with both GPT_ENT_ATTR_BOOTME and
 120                  * GPT_ENT_ATTR_BOOTONCE flags.
 121                  */
 122                 for (; curent < gpthdr->hdr_entries; curent++) {
 123                         ent = &gpttable[curent];
 124                         if (bcmp(&ent->ent_type, uuid, sizeof(uuid_t)) != 0)
 125                                 continue;
 126                         if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTME))
 127                                 continue;
 128                         if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTONCE))
 129                                 continue;
 130                         /* Ok, found one. */
 131                         goto found;
 132                 }
 133                 bootonce = 0;
 134                 curent = 0;
 135         }
 136         for (; curent < gpthdr->hdr_entries; curent++) {
 137                 ent = &gpttable[curent];
 138                 if (bcmp(&ent->ent_type, uuid, sizeof(uuid_t)) != 0)
 139                         continue;
 140                 if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTME))
 141                         continue;
 142                 if (ent->ent_attr & GPT_ENT_ATTR_BOOTONCE)
 143                         continue;
 144                 /* Ok, found one. */
 145                 goto found;
 146         }
 147         if (firsttry) {
 148                 /*
 149                  * No partition with BOOTME flag was found, try to boot from
 150                  * first UFS partition.
 151                  */
 152                 for (curent = 0; curent < gpthdr->hdr_entries; curent++) {
 153                         ent = &gpttable[curent];
 154                         if (bcmp(&ent->ent_type, uuid, sizeof(uuid_t)) != 0)
 155                                 continue;
 156                         /* Ok, found one. */
 157                         goto found;
 158                 }
 159         }
 160         return (-1);
 161 found:
 162         dskp->part = curent + 1;
 163         ent = &gpttable[curent];
 164         dskp->start = ent->ent_lba_start;
 165         if (ent->ent_attr & GPT_ENT_ATTR_BOOTONCE) {
 166                 /*
 167                  * Clear BOOTME, but leave BOOTONCE set before trying to
 168                  * boot from this partition.
 169                  */
 170                 if (hdr_primary_lba > 0) {
 171                         table_primary[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTME;
 172                         gptupdate("primary", dskp, &hdr_primary, table_primary);
 173                 }
 174                 if (hdr_backup_lba > 0) {
 175                         table_backup[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTME;
 176                         gptupdate("backup", dskp, &hdr_backup, table_backup);
 177                 }
 178         }
 179         return (0);
 180 }
 181
 182 static int
 183 gptread_hdr(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
 184     uint64_t hdrlba)
 185 {
 186         uint32_t crc;
 187
 188         if (drvread(dskp, secbuf, hdrlba, 1)) {
 189                 printf("%s: unable to read %s GPT header\n", BOOTPROG, which);
 190                 return (-1);
 191         }
 192         bcopy(secbuf, hdr, sizeof(*hdr));
 193         if (bcmp(hdr->hdr_sig, GPT_HDR_SIG, sizeof(hdr->hdr_sig)) != 0 ||
 194             hdr->hdr_lba_self != hdrlba || hdr->hdr_revision < 0x00010000 ||
 195             hdr->hdr_entsz < sizeof(struct gpt_ent) ||
 196             hdr->hdr_entries > MAXTBLENTS || DEV_BSIZE % hdr->hdr_entsz != 0) {
 197                 printf("%s: invalid %s GPT header\n", BOOTPROG, which);
 198                 return (-1);
 199         }
 200         crc = hdr->hdr_crc_self;
 201         hdr->hdr_crc_self = 0;
 202         if (crc32(hdr, hdr->hdr_size) != crc) {
 203                 printf("%s: %s GPT header checksum mismatch\n", BOOTPROG,
 204                     which);
 205                 return (-1);
 206         }
 207         hdr->hdr_crc_self = crc;
 208         return (0);
 209 }
 210
 211 void
 212 gptbootfailed(struct dsk *dskp)
 213 {
 214
 215         if (!(gpttable[curent].ent_attr & GPT_ENT_ATTR_BOOTONCE))
 216                 return;
 217
 218         if (hdr_primary_lba > 0) {
 219                 table_primary[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
 220                 table_primary[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
 221                 gptupdate("primary", dskp, &hdr_primary, table_primary);
 222         }
 223         if (hdr_backup_lba > 0) {
 224                 table_backup[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
 225                 table_backup[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
 226                 gptupdate("backup", dskp, &hdr_backup, table_backup);
 227         }
 228 }
 229
 230 static void
 231 gptbootconv(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
 232     struct gpt_ent *table)
 233 {
 234         struct gpt_ent *ent;
 235         daddr_t slba;
 236         int table_updated, sector_updated;
 237         int entries_per_sec, nent, part;
 238
 239         table_updated = 0;
 240         entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
 241         for (nent = 0, slba = hdr->hdr_lba_table;
 242              slba < hdr->hdr_lba_table + hdr->hdr_entries / entries_per_sec;
 243              slba++, nent += entries_per_sec) {
 244                 sector_updated = 0;
 245                 for (part = 0; part < entries_per_sec; part++) {
 246                         ent = &table[nent + part];
 247                         if ((ent->ent_attr & (GPT_ENT_ATTR_BOOTME |
 248                             GPT_ENT_ATTR_BOOTONCE |
 249                             GPT_ENT_ATTR_BOOTFAILED)) !=
 250                             GPT_ENT_ATTR_BOOTONCE) {
 251                                 continue;
 252                         }
 253                         ent->ent_attr &= ~GPT_ENT_ATTR_BOOTONCE;
 254                         ent->ent_attr |= GPT_ENT_ATTR_BOOTFAILED;
 255                         table_updated = 1;
 256                         sector_updated = 1;
 257                 }
 258                 if (!sector_updated)
 259                         continue;
 260                 bcopy(&table[nent], secbuf, DEV_BSIZE);
 261                 if (drvwrite(dskp, secbuf, slba, 1)) {
 262                         printf("%s: unable to update %s GPT partition table\n",
 263                             BOOTPROG, which);
 264                 }
 265         }
 266         if (!table_updated)
 267                 return;
 268         hdr->hdr_crc_table = crc32(table, hdr->hdr_entries * hdr->hdr_entsz);
 269         hdr->hdr_crc_self = 0;
 270         hdr->hdr_crc_self = crc32(hdr, hdr->hdr_size);
 271         bzero(secbuf, DEV_BSIZE);
 272         bcopy(hdr, secbuf, hdr->hdr_size);
 273         if (drvwrite(dskp, secbuf, hdr->hdr_lba_self, 1))
 274                 printf("%s: unable to update %s GPT header\n", BOOTPROG, which);
 275 }
 276
 277 static int
 278 gptread_table(const char *which, struct dsk *dskp, struct gpt_hdr *hdr,
 279     struct gpt_ent *table)
 280 {
 281         struct gpt_ent *ent;
 282         int entries_per_sec;
 283         int part, nent;
 284         daddr_t slba;
 285
 286         if (hdr->hdr_entries == 0)
 287                 return (0);
 288
 289         entries_per_sec = DEV_BSIZE / hdr->hdr_entsz;
 290         slba = hdr->hdr_lba_table;
 291         nent = 0;
 292         for (;;) {
 293                 if (drvread(dskp, secbuf, slba, 1)) {
 294                         printf("%s: unable to read %s GPT partition table\n",
 295                             BOOTPROG, which);
 296                         return (-1);
 297                 }
 298                 ent = (struct gpt_ent *)secbuf;
 299                 for (part = 0; part < entries_per_sec; part++, ent++) {
 300                         bcopy(ent, &table[nent], sizeof(table[nent]));
 301                         if (++nent >= hdr->hdr_entries)
 302                                 break;
 303                 }
 304                 if (nent >= hdr->hdr_entries)
 305                         break;
 306                 slba++;
 307         }
 308         if (crc32(table, nent * hdr->hdr_entsz) != hdr->hdr_crc_table) {
 309                 printf("%s: %s GPT table checksum mismatch\n", BOOTPROG, which);
 310                 return (-1);
 311         }
 312         return (0);
 313 }
 314
 315 int
 316 gptread(struct dsk *dskp, char *buf)
 317 {
 318         uint64_t altlba;
 319
 320         /*
 321          * Read and verify both GPT headers: primary and backup.
 322          */
 323
 324         secbuf = buf;
 325         hdr_primary_lba = hdr_backup_lba = 0;
 326         curent = -1;
 327         bootonce = 1;
 328         dskp->start = 0;
 329
 330         if (gptread_hdr("primary", dskp, &hdr_primary, 1) == 0 &&
 331             gptread_table("primary", dskp, &hdr_primary, table_primary) == 0) {
 332                 hdr_primary_lba = hdr_primary.hdr_lba_self;
 333                 gpthdr = &hdr_primary;
 334                 gpttable = table_primary;
 335         }
 336
 337         if (hdr_primary_lba > 0) {
 338                 /*
 339                  * If primary header is valid, we can get backup
 340                  * header location from there.
 341                  */
 342                 altlba = hdr_primary.hdr_lba_alt;
 343         } else {
 344                 altlba = drvsize(dskp);
 345                 if (altlba > 0)
 346                         altlba--;
 347         }
 348         if (altlba == 0)
 349                 printf("%s: unable to locate backup GPT header\n", BOOTPROG);
 350         else if (gptread_hdr("backup", dskp, &hdr_backup, altlba) == 0 &&
 351             gptread_table("backup", dskp, &hdr_backup, table_backup) == 0) {
 352                 hdr_backup_lba = hdr_backup.hdr_lba_self;
 353                 if (hdr_primary_lba == 0) {
 354                         gpthdr = &hdr_backup;
 355                         gpttable = table_backup;
 356                         printf("%s: using backup GPT\n", BOOTPROG);
 357                 }
 358         }
 359
 360         /*
 361          * Convert all BOOTONCE without BOOTME flags into BOOTFAILED.
 362          * BOOTONCE without BOOTME means that we tried to boot from it,
 363          * but failed after leaving gptboot and machine was rebooted.
 364          * We don't want to leave partitions marked as BOOTONCE only,
 365          * because when we boot successfully start-up scripts should
 366          * find at most one partition with only BOOTONCE flag and this
 367          * will mean that we booted from that partition.
 368          */
 369         if (hdr_primary_lba != 0)
 370                 gptbootconv("primary", dskp, &hdr_primary, table_primary);
 371         if (hdr_backup_lba != 0)
 372                 gptbootconv("backup", dskp, &hdr_backup, table_backup);
 373
 374         if (hdr_primary_lba == 0 && hdr_backup_lba == 0)
 375                 return (-1);
 376         return (0);
 377 }